1 /* Copyright (C) 2011-2017 B.A.T.M.A.N. contributors:
3 * Linus Lüssing, Marek Lindner
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of version 2 of the GNU General Public
7 * License as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 #include "bat_v_elp.h"
21 #include <linux/atomic.h>
22 #include <linux/bitops.h>
23 #include <linux/byteorder/generic.h>
24 #include <linux/errno.h>
25 #include <linux/etherdevice.h>
26 #include <linux/ethtool.h>
28 #include <linux/if_ether.h>
29 #include <linux/jiffies.h>
30 #include <linux/kernel.h>
31 #include <linux/kref.h>
32 #include <linux/netdevice.h>
33 #include <linux/nl80211.h>
34 #include <linux/random.h>
35 #include <linux/rculist.h>
36 #include <linux/rcupdate.h>
37 #include <linux/rtnetlink.h>
38 #include <linux/skbuff.h>
39 #include <linux/stddef.h>
40 #include <linux/string.h>
41 #include <linux/types.h>
42 #include <linux/workqueue.h>
43 #include <net/cfg80211.h>
46 #include "bat_v_ogm.h"
47 #include "hard-interface.h"
49 #include "originator.h"
55 * batadv_v_elp_start_timer - restart timer for ELP periodic work
56 * @hard_iface: the interface for which the timer has to be reset
58 static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
62 msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
63 msecs += prandom_u32() % (2 * BATADV_JITTER);
65 queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
66 msecs_to_jiffies(msecs));
70 * batadv_v_elp_get_throughput - get the throughput towards a neighbour
71 * @neigh: the neighbour for which the throughput has to be obtained
73 * Return: The throughput towards the given neighbour in multiples of 100kpbs
74 * (a value of '1' equals to 0.1Mbps, '10' equals 1Mbps, etc).
76 static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
78 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
79 struct ethtool_link_ksettings link_settings;
80 struct net_device *real_netdev;
81 struct station_info sinfo;
85 /* if the user specified a customised value for this interface, then
88 throughput = atomic_read(&hard_iface->bat_v.throughput_override);
92 /* if this is a wireless device, then ask its throughput through
95 if (batadv_is_wifi_hardif(hard_iface)) {
96 if (!batadv_is_cfg80211_hardif(hard_iface))
97 /* unsupported WiFi driver version */
98 goto default_throughput;
100 real_netdev = batadv_get_real_netdev(hard_iface->net_dev);
102 goto default_throughput;
104 ret = cfg80211_get_station(real_netdev, neigh->addr, &sinfo);
106 dev_put(real_netdev);
107 if (ret == -ENOENT) {
108 /* Node is not associated anymore! It would be
109 * possible to delete this neighbor. For now set
110 * the throughput metric to 0.
115 goto default_throughput;
116 if (!(sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)))
117 goto default_throughput;
119 return sinfo.expected_throughput / 100;
122 /* if not a wifi interface, check if this device provides data via
123 * ethtool (e.g. an Ethernet adapter)
125 memset(&link_settings, 0, sizeof(link_settings));
127 ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings);
130 /* link characteristics might change over time */
131 if (link_settings.base.duplex == DUPLEX_FULL)
132 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
134 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
136 throughput = link_settings.base.speed;
137 if (throughput && (throughput != SPEED_UNKNOWN))
138 return throughput * 10;
142 if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
143 batadv_info(hard_iface->soft_iface,
144 "WiFi driver or ethtool info does not provide information about link speeds on interface %s, therefore defaulting to hardcoded throughput values of %u.%1u Mbps. Consider overriding the throughput manually or checking your driver.\n",
145 hard_iface->net_dev->name,
146 BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
147 BATADV_THROUGHPUT_DEFAULT_VALUE % 10);
148 hard_iface->bat_v.flags |= BATADV_WARNING_DEFAULT;
151 /* if none of the above cases apply, return the base_throughput */
152 return BATADV_THROUGHPUT_DEFAULT_VALUE;
156 * batadv_v_elp_throughput_metric_update - worker updating the throughput metric
157 * of a single hop neighbour
158 * @work: the work queue item
160 void batadv_v_elp_throughput_metric_update(struct work_struct *work)
162 struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
163 struct batadv_hardif_neigh_node *neigh;
165 neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
167 neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
170 ewma_throughput_add(&neigh->bat_v.throughput,
171 batadv_v_elp_get_throughput(neigh));
173 /* decrement refcounter to balance increment performed before scheduling
176 batadv_hardif_neigh_put(neigh);
180 * batadv_v_elp_wifi_neigh_probe - send link probing packets to a neighbour
181 * @neigh: the neighbour to probe
183 * Sends a predefined number of unicast wifi packets to a given neighbour in
184 * order to trigger the throughput estimation on this link by the RC algorithm.
185 * Packets are sent only if there there is not enough payload unicast traffic
186 * towards this neighbour..
188 * Return: True on success and false in case of error during skb preparation.
191 batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
193 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
194 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
195 unsigned long last_tx_diff;
200 /* this probing routine is for Wifi neighbours only */
201 if (!batadv_is_wifi_hardif(hard_iface))
204 /* probe the neighbor only if no unicast packets have been sent
205 * to it in the last 100 milliseconds: this is the rate control
206 * algorithm sampling interval (minstrel). In this way, if not
207 * enough traffic has been sent to the neighbor, batman-adv can
208 * generate 2 probe packets and push the RC algorithm to perform
211 last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
212 if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
215 probe_len = max_t(int, sizeof(struct batadv_elp_packet),
216 BATADV_ELP_MIN_PROBE_SIZE);
218 for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
219 elp_skb_len = hard_iface->bat_v.elp_skb->len;
220 skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
221 probe_len - elp_skb_len,
226 /* Tell the skb to get as big as the allocated space (we want
227 * the packet to be exactly of that size to make the link
228 * throughput estimation effective.
230 skb_put_zero(skb, probe_len - hard_iface->bat_v.elp_skb->len);
232 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
233 "Sending unicast (probe) ELP packet on interface %s to %pM\n",
234 hard_iface->net_dev->name, neigh->addr);
236 batadv_send_skb_packet(skb, hard_iface, neigh->addr);
243 * batadv_v_elp_periodic_work - ELP periodic task per interface
244 * @work: work queue item
246 * Emits broadcast ELP message in regular intervals.
248 static void batadv_v_elp_periodic_work(struct work_struct *work)
250 struct batadv_hardif_neigh_node *hardif_neigh;
251 struct batadv_hard_iface *hard_iface;
252 struct batadv_hard_iface_bat_v *bat_v;
253 struct batadv_elp_packet *elp_packet;
254 struct batadv_priv *bat_priv;
259 bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
260 hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
261 bat_priv = netdev_priv(hard_iface->soft_iface);
263 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
266 /* we are in the process of shutting this interface down */
267 if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
268 (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
271 /* the interface was enabled but may not be ready yet */
272 if (hard_iface->if_status != BATADV_IF_ACTIVE)
275 skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC);
279 elp_packet = (struct batadv_elp_packet *)skb->data;
280 elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno));
281 elp_interval = atomic_read(&hard_iface->bat_v.elp_interval);
282 elp_packet->elp_interval = htonl(elp_interval);
284 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
285 "Sending broadcast ELP packet on interface %s, seqno %u\n",
286 hard_iface->net_dev->name,
287 atomic_read(&hard_iface->bat_v.elp_seqno));
289 batadv_send_broadcast_skb(skb, hard_iface);
291 atomic_inc(&hard_iface->bat_v.elp_seqno);
293 /* The throughput metric is updated on each sent packet. This way, if a
294 * node is dead and no longer sends packets, batman-adv is still able to
295 * react timely to its death.
297 * The throughput metric is updated by following these steps:
298 * 1) if the hard_iface is wifi => send a number of unicast ELPs for
299 * probing/sampling to each neighbor
300 * 2) update the throughput metric value of each neighbor (note that the
301 * value retrieved in this step might be 100ms old because the
302 * probing packets at point 1) could still be in the HW queue)
305 hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
306 if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
307 /* if something goes wrong while probing, better to stop
308 * sending packets immediately and reschedule the task
312 if (!kref_get_unless_zero(&hardif_neigh->refcount))
315 /* Reading the estimated throughput from cfg80211 is a task that
316 * may sleep and that is not allowed in an rcu protected
317 * context. Therefore schedule a task for that.
319 ret = queue_work(batadv_event_workqueue,
320 &hardif_neigh->bat_v.metric_work);
323 batadv_hardif_neigh_put(hardif_neigh);
328 batadv_v_elp_start_timer(hard_iface);
334 * batadv_v_elp_iface_enable - setup the ELP interface private resources
335 * @hard_iface: interface for which the data has to be prepared
337 * Return: 0 on success or a -ENOMEM in case of failure.
339 int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
341 static const size_t tvlv_padding = sizeof(__be32);
342 struct batadv_elp_packet *elp_packet;
343 unsigned char *elp_buff;
348 size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN + tvlv_padding;
349 hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
350 if (!hard_iface->bat_v.elp_skb)
353 skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
354 elp_buff = skb_put_zero(hard_iface->bat_v.elp_skb,
355 BATADV_ELP_HLEN + tvlv_padding);
356 elp_packet = (struct batadv_elp_packet *)elp_buff;
358 elp_packet->packet_type = BATADV_ELP;
359 elp_packet->version = BATADV_COMPAT_VERSION;
361 /* randomize initial seqno to avoid collision */
362 get_random_bytes(&random_seqno, sizeof(random_seqno));
363 atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno);
365 /* assume full-duplex by default */
366 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
368 /* warn the user (again) if there is no throughput data is available */
369 hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT;
371 if (batadv_is_wifi_hardif(hard_iface))
372 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
374 INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq,
375 batadv_v_elp_periodic_work);
376 batadv_v_elp_start_timer(hard_iface);
384 * batadv_v_elp_iface_disable - release ELP interface private resources
385 * @hard_iface: interface for which the resources have to be released
387 void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface)
389 cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq);
391 dev_kfree_skb(hard_iface->bat_v.elp_skb);
392 hard_iface->bat_v.elp_skb = NULL;
396 * batadv_v_elp_iface_activate - update the ELP buffer belonging to the given
398 * @primary_iface: the new primary interface
399 * @hard_iface: interface holding the to-be-updated buffer
401 void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface,
402 struct batadv_hard_iface *hard_iface)
404 struct batadv_elp_packet *elp_packet;
407 if (!hard_iface->bat_v.elp_skb)
410 skb = hard_iface->bat_v.elp_skb;
411 elp_packet = (struct batadv_elp_packet *)skb->data;
412 ether_addr_copy(elp_packet->orig,
413 primary_iface->net_dev->dev_addr);
417 * batadv_v_elp_primary_iface_set - change internal data to reflect the new
419 * @primary_iface: the new primary interface
421 void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface)
423 struct batadv_hard_iface *hard_iface;
425 /* update orig field of every elp iface belonging to this mesh */
427 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
428 if (primary_iface->soft_iface != hard_iface->soft_iface)
431 batadv_v_elp_iface_activate(primary_iface, hard_iface);
437 * batadv_v_elp_neigh_update - update an ELP neighbour node
438 * @bat_priv: the bat priv with all the soft interface information
439 * @neigh_addr: the neighbour interface address
440 * @if_incoming: the interface the packet was received through
441 * @elp_packet: the received ELP packet
443 * Updates the ELP neighbour node state with the data received within the new
446 static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv,
448 struct batadv_hard_iface *if_incoming,
449 struct batadv_elp_packet *elp_packet)
452 struct batadv_neigh_node *neigh;
453 struct batadv_orig_node *orig_neigh;
454 struct batadv_hardif_neigh_node *hardif_neigh;
456 s32 elp_latest_seqno;
458 orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig);
462 neigh = batadv_neigh_node_get_or_create(orig_neigh,
463 if_incoming, neigh_addr);
467 hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr);
471 elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno;
472 seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno;
474 /* known or older sequence numbers are ignored. However always adopt
475 * if the router seems to have been restarted.
477 if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE)
480 neigh->last_seen = jiffies;
481 hardif_neigh->last_seen = jiffies;
482 hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno);
483 hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval);
487 batadv_hardif_neigh_put(hardif_neigh);
490 batadv_neigh_node_put(neigh);
493 batadv_orig_node_put(orig_neigh);
497 * batadv_v_elp_packet_recv - main ELP packet handler
498 * @skb: the received packet
499 * @if_incoming: the interface this packet was received through
501 * Return: NET_RX_SUCCESS and consumes the skb if the packet was peoperly
502 * processed or NET_RX_DROP in case of failure.
504 int batadv_v_elp_packet_recv(struct sk_buff *skb,
505 struct batadv_hard_iface *if_incoming)
507 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
508 struct batadv_elp_packet *elp_packet;
509 struct batadv_hard_iface *primary_if;
510 struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
512 int ret = NET_RX_DROP;
514 res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN);
518 if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
521 /* did we receive a B.A.T.M.A.N. V ELP packet on an interface
522 * that does not have B.A.T.M.A.N. V ELP enabled ?
524 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
527 elp_packet = (struct batadv_elp_packet *)skb->data;
529 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
530 "Received ELP packet from %pM seqno %u ORIG: %pM\n",
531 ethhdr->h_source, ntohl(elp_packet->seqno),
534 primary_if = batadv_primary_if_get_selected(bat_priv);
538 batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming,
541 ret = NET_RX_SUCCESS;
542 batadv_hardif_put(primary_if);
545 if (ret == NET_RX_SUCCESS)